<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>输出1至50中是7的倍数的数值之和</title>
	</head>
	<body>
		<script>
			var num=0;
			var sum=0;
			while(num<=49){
				sum=sum+num;
				num=num+7;
			}
			document.write(sum);
		</script>
	</body>
</html>
